The present invention relates to an arrangement on a packing container of the type which is of a substantially parallelepipedic main shape with a fold-out pouring spout that is delimited from an upper wall of the packing container by means of linear weakenings which extend in the direction from the corner of the pouring spout connected to the upper wall toward a sealing fin that runs centrally over the upper wall.
Packing containers for liquid contents, e.g., milk, juice or the like, are frequently manufactured at present from a flexible, semirigid packing laminate that comprises a carrier layer of fibrous material, e.g., paper, and outer, watertight layers of themoplastic material, usually polyethylene. The laminate is fed to a packaging machine in the form of a web or sheets and is folded, formed and sealed to produce a filled packing container of the desired, e.g., parallelepipedic, shape. A packing container of this main type is seen in Swedish Pat. No. 781822-8.
When the finished packing container is to be opened and the contents are to be poured out, a removable part at the upper end of the packing container is broken, torn or cut-off so that the contents become accessible. To facilitate the pouring out of the contents, the packing container frequently is also provided with some form of built-in pouring spout which can be folded out after the opening. The pouring spout usually comprises a number of triangular laminate panels which are connected to one another via weakening lines in the laminate. A part of the triangular pouring spout panels is also connected, inter alia, to the upper wall panel of the packing container from which the panels are again separated by means of weakening lines. The shape and the mutual placement of the different triangular pouring spout panels along with the presence of weakening lines between the panels and adjoining parts of the packing container proper, make it possible to form an effective pouring spout which allows emptying of the contents of the packing container in a collective jet. However, from the time of manufacture of the packing container the triangular pouring spout panels have been arranged in an inwardly folded position in accordance with the main shape of the packing container and have been retained in this position thereafter up to the opening of the packing container. Accordingly, the folding outward and forming of the pouring spout will offer a certain resistance. This resistance is a function of a number of different factors, such as the rigidity and flexibility of the packing laminate, the shape of the pouring spout panel and the adjoining wall panel, the strength of the weakening lines, the method of formation of the packing container, and the storage period. Under unfavorable circumstances, several of these factors may be jointly effective in a negative direction so that the outward turning and forming of the pouring spout becomes difficult to realize. These difficulties have been experienced in the prior art and it has been attempted to overcome these difficulties through a suitable choice of material and through selective strengthening and weakening of weakening lines so that a simpler and to some extent automatic outward folding of the pouring spout is obtained. This has been partly successful but involves at the same time various disadvantages which occur, in particular, during the handling and forming of the packing laminate into packing containers. It has been found, for example, that the required and more pronounced weakening lines easily lead to breaks in the laminate during formation, which breaks resulted in packing containers that leaked. A packing container of the main type described above is seen, e.g., in the Swedish Pat. No. 781822-8 mentioned earlier, to which reference is made.
It is an object of the present invention to provide a packing container with a fold-out pouring spout that is not subject to the disadvantages of the arrangements known previously.
It is a further object of the present invention to provide a packing container with a fold-out pouring spout that is simple to fold out and to form independent of the properties of the packing laminate chosen.
Finally, it is a further object of the present invention to provide a packing container with a fold-out pouring spout, which packing container is simple in principle to manufacture through the use of known methods and arrangements.
These and other objects have been achieved in accordance with the invention in that a packing container of the type described above has been given the characteristics that the weakening lines extend at unequal angles towards the sealing fin.
Owing to the special design of the weakening lines which delimit the fold-out pouring spout from the main part of the upper surface of the packing container, the unfolding of the crease lines is spread in time as the pouring spout is folded out so that the material is folded first along weakening lines of the one side and then along weakening lines of the other side. Thus, the packing laminate does not have to be folded open at the same time along weakening lines of both sides of the spout and no peak force arises which has proved to make easier the necessary bending or folding of the laminate. As a result of the asymmetric placing of the weakening lines the folding open of the material, moreover, will produce a pouring spout that is stronger and more durable. Consequentially, the prospect of the formed pouring spout collapsing is greatly diminished due to the flexibility and rigidity of the material.